Excusses my ignorace towards EDM, what is in the VTi, doesnt that have a b16a2? or is that the VXi? NEways, all the b series engines will work, b18b is good for boost gsr, type r (both of them) and b16a2 are all great na engines. What are you planning on doing with this car (y do you want to go fast, autoX, drag, fun car?)
if you have a b16a2 in there already, keep it. It is a great engine and has alot of room for improvement. You could build up the bottom end and the head and you will have a fast car. Or you can go turbo on it. anyways keep that engine.